Production of l-acetoxy-j



Patented Feb. 12, 1952 UNITED STATES ATNT OFFICE PRODUCTION OF 1-ACETOXY-3- BUTEN-Z-ONE Joseph M. Wilkinson, Jr., Easton, Pa., assignor to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application October 10, 1950, Serial No. 189,488

4 Claims. (01. 260488) 1 2 This invention relates to a method for prepar- In order to obtain a. satisfactory yield, it is deing l-acetoxy-B-buten-Z-one comprising heating sirable to employ an excess of acetic anhydride a mixture of 1,4-dihydroxy-2-butanone with an in the reaction and as a general rule at least two excess of acetic anhydride in an inert solvent. molecular proportions of acetic anhydride are l-acetoxy-3-buten-2-one has heretofore been 5 used for each molecular proportion of 1,4-dihyobtained by syntheses involving the use of merdroxy-2-butanone. However, the process is opcuric catalysts, i. e., it has been obtained by erative when equal molecular proportions are emtreatment of 1,4-diacetoxy-2-butyne in aqueous ployed and, in fact, some of the product is formed acetic acid with mercuric acetate (Lozach, Bull. when less than the theoretical amount of acetic soc. chim., 11, 514515 (1944)) and by treatment anhydride is used.

of 4-aeetoxy-2-butyn-1-o1 with acid mercuric The details of the present invention will be apion in non-aqueous solution (my copending apparent from a consideration of the following speplication Serial No. 786,161, now Patent No. cific example:

2,524,025) Example The thus obtained product, l-acetoxy-Zi-buten- 2-one, is of interest in the fields of polymers, To a Solution of 136 either for t production of homopolymers or in tanone in 400 ml. glacial acetic acid is added 500 reactions with other monomers. In addition, its 1111- a c y e- The resulting Solution is chemical reactivity in such as to make it an imheated at for The acetic portant intermediate in the synthesis of a wide d d SS acetic y de e removed variety of chemical compounds having utility in under diminished pressure. Distillation of the the field of pharmaceuticals, dyestuiis and surresidue es yface active agents. However, when 1-acetoxy-3- in y d of -65% of the theoretical t was prepared according t previous amount. The residue largely consists of resinous methods, employing mercuric salts as catalysts, eendehsetion p the product was contaminated with metallic e reaction y be characterized y the mercury which was difiicult to remove by distillalowing equationtion. The presence oi. mercury in the product 0 0 has a deleterious effect in many chemical reac- HOCHIELCHQCHNH i 32 AcO CH2JJJ CH=dH,

tions. In addition, in prior art procedures, particularly by the method of Lozach Bull. soc. since 1 a,cet y-3-buten-2-0neisareadfly polyehim, 11, 514-515 (1944), there is also Obtained merizable substance, the yield of the desired monin addition to l-acetoxy-3-buten-2-0ne, the anomer can be improved b incorporating in the retieipated 1,4-dieeet0Xy-2-buten0neaction mixture, either before or during the reac-' It has now been Observed that 35 tion (at least prior to isolation of the 1-acetoxy-3- buten-Z-one may be obtained from 1,4-dihybuten z one) a mall amount of a, polymerizadroxy-z-butanone by treatment with ace tion inhibitor of a type normally employed for the hydride in acetic acid. Surprisingly, 'by such a inhibition fv1ny1 t Asexamples procedure, no significant quantity of the anticif suitable inhibitors of thiS type may be pated 1,4-diacetoxy-2-butanone is obtained. 40 tioned hydroquinone, p-tert.-butyl catechol, 1. I have found that by merely heating fur, metallic copper, etc. Such inhibitors are efhYdYOXY'Z'bJtanOnB Preferably in an inert fective when employed in minor amount, usually vent, with excess acetic anhydride, dehydration Within the range of 05 to 2 percent of the and acetylation occur and 1-acetoxy-3-buten-2- t 3 -b 1-, 2

one is obtained in good yield. The process is op- I claim;

erative over a relatively wide temperature range A method of preparing t 1-,

and temperatures within the range of 75 to 130 2-one which comprises heating 1,4-dihydroxy-2- C. h ve b e f d to be Operative w v butanone with excess acetic anhydride inan inert critical limits of temperature have not been esp m;

tablished. 2. The method as defined in claim 1 wherein I have found that glacial acetic acid m y the solvent employed is glacial acetic acid. vantageously 'be used as inert solvent for the re- 3. The method as defined in claim 1 wherein action- How ver, if esired, other inert solvents there is present in the reaction mixture a minor Such as a Py d e, boxylic acid esters, amount of polymerization inhibitor.

etc., or excess acetic anhydride alone may be used. 4. The method as defined in claim 3 wherein The amount of solvent is not extremely critical the inert solvent is glacial acetic acid.

and as a general rule from 0.5 to 2 volumes of JOSEPH M. WILKINSON, JR. solvent are used for each volume of acetic anhydride employed in the reaction. No references cited. 

1. A METHOD OF PREPARING 1-ACETOXY-3-BUTEN2-ONE WHICH COMPRISES HEATING 1,4-DIHYDROXY-2BUTANONE WITH EXCESS ACETIC ANHYDRIDE IN AN INERT SOLVENT. 